Gas, e.g., exhaust gas, treatment devices such as catalytic converters, evaporative emissions devices, hydrocarbon scrubbing devices, diesel particulate traps, non-thermal plasma reactors, and the like, are employed in various applications to physically and/or catalytically treat environmentally unfriendly gas emissions. Such gas treatment devices incorporate a substrate, support, monolith, or brick, which includes a catalyst material coated thereon. A mounting device such as a mat support material comprising an intumescent material, non-intumescent material, or a combination of both, is disposed about the substrate forming a mat support material/substrate subassembly, prior to being inserted into the gas treatment device""s housing.
One method for inserting the mat support material/substrate subassembly into the housing comprises using a stuffing cone. In this method, the outlet of the stuffing cone, which is disposed adjacent to the inlet of the housing, has an inner diameter less than the inner diameter of the housing. As the mat support material/substrate subassembly moves through the stuffing cone toward the housing, the stuffing cone compresses the mat support material about the substrate so that the subassembly can be disposed into the housing. More particularly, as the mat support material/substrate subassembly slides against the inwardly tapered interior of the stuffing cone, the mat support material compresses about the substrate until the mat support material substrate subassembly has an outer diameter less than the housing outer diameter. At this point, the mat support material/substrate subassembly is pushed into the housing.
Generally, the stuffing cone""s diameter is less than the diameter of the smallest housing to be stuffed using that particular stuffing cone to ensure the subassembly is sufficiently compressed to be inserted into the housing. In some cases, the stuffing cone overly compresses the mat support (e.g., the housing inner diameter is substantially larger than the stuffing cone inner diameter. This design causes the mat support material to exert excessive force about the substrate. In contrast, it is predicted that the housing exerts a greatly reduced level of pressure per square inch about the subassembly to retain it in place after disposal. The additional pressure exerted during the subassembly""s compression in the stuffing cone reduces the mat support material""s retentive capabilities, increases the over compression of the mat support material, and increases the probability of substrate breakage.
Also, in order to effectively stuff the matted substrate into the housing, the housing must be sized to the desired mat density level following the low-pressure stuffing operation. This process is limiting, however, in that it is not suitable for non-rounded substrates or material with excessive spring back properties.
The present disclosure relates to embodiments of a stuffing apparatus, a method for forming a gas treatment device or similar device, and the device formed thereby. The method for forming a gas treatment device comprises: disposing the housing at a locating cavity positioned near a second end of a funnel, wrapping a substrate with a mat support material to form a subassembly, disposing a pusher disc in physical contact with a subassembly first side, and disposing a retainer disc of a retainer detail in physical contact with a subassembly second side, wherein the retainer detail extends through the second end of the funnel toward a first end of the funnel to engage the subassembly second side. Sufficient force is applied on the subassembly with the pusher detail to slidably move the subassembly toward the second end, and an opposite and lesser force is applied on the subassembly with the retainer detail. The subassembly is moved from the funnel into the housing to form the gas treatment device.
In one embodiment, the stuffing cone apparatus comprises: a funnel having a first end and a second end, with the second end having a smaller diameter than the first end, a pusher detail comprising a pusher disc perpendicularly disposed on an end of a pusher arm, wherein the pusher detail is slideable within the funnel, and a retainer detail comprising a retainer disc perpendicularly disposed to an end of a retainer arm, wherein the retainer detail is slideable within the funnel. The retainer disc and the pusher disc are capable of physically contacting opposite sides of a substrate within the funnel.
In another embodiment, the stuffing cone apparatus comprises a means for compressing a mat support material about a substrate, a means for physically contact with a subassembly first side, and a means for physically contacting a subassembly second side. The means for physically contacting a subassembly second side is capable of extending through a second end of the means for compressing a mat support material about a substrate toward a first end of the means for compressing a mat support material about a substrate to engage the subassembly second side.
The above-described and other features will be appreciated and understood by those skilled in the art from the following detailed description, drawings, and appended claims.